It is known practice to transmit data between two communication units asymmetrically, i.e. to produce different data rates in the two transmission directions. This is particularly appropriate when the data rates or bandwidths in the two transmission directions differ greatly.
To produce asymmetrical links, it is known practice to connect two communication units via a fiber-optic link, for example. The fiber-optic link has either two fibers (one for each respective transmission direction) or one fiber, in which case data are transmitted in half-duplex mode or—if different wavelengths are used—simultaneously.
In this context, it is usual to use the same technology for both transmission directions. However, this is inefficient in as much as an asymmetrical data transmission requires a high bandwidth only for one transmission direction. By way of example, a link between a camera, a control unit and a screen requires a high bandwidth in the Gbit/s range only for transmitting data from the camera to the screen. By contrast, the control signals for the camera which are transmitted in the opposite direction by the control unit generally require only a low bandwidth in the Kbit/s range.
The existing systems for asymmetrical data transmission are thus distinguished by incomplete utilization of the data channel with the low data rates, which results in this data channel being relatively cost-intensive in terms of the transmitted data rate.
In addition, “media converters” are known which extend the range of existing copper links by interposing an optical transmission link in an electrical transmission link. In this case too, data transmission is effected in both transmission directions using the same technology.